Substrate container valve assemblies

ABSTRACT

A substrate container includes a container portion having an open side or bottom, and a door to sealingly close the open side or bottom, one of the door and the container portion defining access structure. The substrate container additionally includes a check-valve assembly, the check-valve assembly being retained with respect to the access structure to provide fluid communication with an interior of the substrate container. The check-valve assembly includes a grommet, the grommet being formed of an elastomeric material. A valve seat is disposed within the grommet, the valve seat being integrally formed with the grommet according to one aspect, and being formed of a separate piece according to another aspect. An elastomeric valve member, specifically an elastomeric umbrella valve member according to one aspect, is disposed within the grommet and held to engage the valve seat, thereby restricting fluid flow through the check-valve assembly with respect to the interior of the substrate container.

PRIORITY CLAIM

This application claims priority to U.S. Provisional Application No.62/086,022, filed Dec. 1, 2014.

BACKGROUND

In general, substrate containers or carriers are used for transportingand/or storing batches of silicon wafers or magnetic disks before,during and after processing of the wafers or disks. The wafers can beprocessed into integrated circuits and the disks can be processed into amagnetic storage disks for computers. The terms wafer, disk, andsubstrate are used interchangeably herein and any of these terms canrefer to semiconductor wafers, magnetic disks, flat panel substrates,reticles, and other such substrates, unless otherwise indicated.

The processing of wafer disks into integrated circuit chips ofteninvolves multiple steps where the disks are processed at variousprocessing stations, and stored and transported between processingsteps. Due to the delicate nature of the disks and their susceptibilityto contamination by particles or chemicals, it is vital that they areproperly protected throughout this procedure. Wafer containers have beenused to provide this necessary protection. Additionally, since theprocessing of disks is generally automated, it is necessary for disks tobe precisely positioned relative to the processing equipment for therobotic removal and insertion of the wafers. Another purpose of a wafercontainer is to securely hold the wafer disks during transport. Theterms wafer containers, carriers, cassettes, transport/storage bins, andthe like, are used interchangeably herein unless otherwise indicated.

During processing of semiconductor wafers or magnetic disks, thepresence of or generation of particulates presents very significantcontamination problems. Contamination is accepted as the single largestcause of yield loss in the semi-conductor industry. As the size ofintegrated circuitry has continued to be reduced, the size of particleswhich can contaminate an integrated circuit has also become smaller,making minimization of contaminants all the more critical. Contaminantsin the form of particles may be generated by abrasion such as therubbing or scraping of the carrier with the wafers, with the carriercovers or enclosures, with storage racks, with other carriers or withprocessing equipment. Additionally, particulates such as dust can beintroduced into the enclosures through the openings or joints in thecovers and/or enclosures. Thus, a critical function of wafer carriers isto protect the wafers therein from such contaminants.

Containers are generally configured to axially arrange the wafers ordisks in slots, and to support the wafers or disks by or near theirperipheral edges. The wafers or disks are conventionally removable fromthe containers in a radial direction upwardly or laterally. Thecontainers may have a shell portion with a lower opening, a door tolatch into the lower opening, and a discrete carrier that rests on thedoor. This configuration, known as a SMIF pod, is illustrated in U.S.Pat. Nos. 4,995,430 and 4,815,912, both owned by the owner of theinstant application and both incorporated herein by reference.Additionally, wafer carrier assemblies can have front openings withdoors that latch onto front openings, which are known as FOUPs or FOSBs,and are described in, for example, U.S. Pat. Nos. 6,354,601, 5,788,082and 6,010,008, all of which are incorporated by reference herein. Incertain configurations, the bottom covers or doors, front doors or thecontainer portions have been provided with openings or passageways tofacilitate the introduction and/or exhaustion of gases such as nitrogenor other purified gasses, into the wafer carrier assemblies to displaceambient air that might have contaminants.

Wafer containers and reticle containers known in the art have usedvarious connection or coupling mechanisms for fluidly interfacing theflow passageways of the wafer containers to fluid supply and pressure orvacuum sources. Such attachment and sealing requires specializedcomponents which may be of complex configuration. Certain currentdesigns include a check valve having a frame, a plunger, O-rings andmetal spring, one or more of which can lead to wafer contaminationthrough the generation of particulates or other contaminants.Additionally, some purge-valve designs are susceptible to compressiveforces during installation, potentially deforming a frame of the checkvalve and leading to leakage.

SUMMARY

According to one aspect of the disclosure, a substrate containerincludes a container portion having an open side or bottom, and a doorto sealingly close the open side or bottom, one of the door and thecontainer portion defining access structure. The substrate containeradditionally includes a check-valve assembly, the check-valve assemblybeing retained with respect to the access structure to provide fluidcommunication with an interior of the substrate container. Thecheck-valve assembly includes a grommet, the grommet being formed of anelastomeric material. A valve seat is disposed within the grommet, thevalve seat being integrally formed with the grommet according to oneaspect, and being formed of a separate piece according to anotheraspect. An elastomeric disk shaped valve member retained by a centralstem to the valve seat, for example an elastomeric umbrella valvemember, according to one aspect, is disposed within the grommet and heldto engage the valve seat, thereby restricting fluid flow through thecheck-valve assembly with respect to the interior of the substratecontainer.

The number of parts within a check-valve assembly is substantiallyreduced, in some cases including only two parts: an elastomeric grommethaving internal structure defining one or more valve seats, and anassociated elastomeric umbrella check valve member. The elastomericvalve member optionally is reversible within the grommet to restrictfluid flow through the check-valve assembly in an opposite direction.According to another aspect, a check-valve assembly includes only threeparts: an elastomeric grommet, a substantially rigid housing within thegrommet, and an elastomeric umbrella valve member.

A feature and advantage of embodiments of the invention is that anelastomeric disk shaped valve member cooperates with a flat elastomericvalve seat in a valve. The utilization of elastomeric valve componentassembling and functioning with another elastomeric valve componentprovides ease of assembly and a high level of sealing integrity. Withrespect to an umbrella valve with a disk portion and a stem portion, theelastomeric stem portion in inserted into an opening defined byelastomeric material and the disk seats against the elastomeric valveseat. In embodiment the disk shaped member has a convex shape facingaway from the valve seat in an unactuated state and the disk inverts,when actuated by gas passing through the valve, such that the shape isconcave or flat facing away from the valve seat. In other embodiments,the disk may be flat in the unactuated state and change to a concaveshape facing away from the valve seat when actuated with gas passingthrough the valve. In other embodiments the disk may be flat and bepivotally attached to the valve seat at a periphery of the disk andoperate as a flap.

According to another aspect, a check-valve assembly is disposed in astacked configuration, end-to-end with respect to a grommet. Varioushousings and retention mechanisms for check-valve assemblies also aredisclosed. Other check-valve assemblies, check-valve modules, andassociated methods are also disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of a substrate containerassembly, according to an embodiment of the disclosure;

FIG. 2 is a bottom view of an example bottom cover of the FIG. 1assembly;

FIG. 3 is a perspective view of a front opening substrate containeraccording to an embodiment of the disclosure;

FIG. 4 is a bottom view of the substrate container of FIG. 3;

FIG. 5 is a perspective view of receiving structure according to anembodiment of the disclosure;

FIG. 6 is an exploded view of a check-valve module, according to anembodiment of the disclosure;

FIG. 7 is a cross-sectional view of an assembled module formed of theFIG. 6 components;

FIG. 8 is a top perspective view of a grommet shown in FIGS. 6-7;

FIG. 9 is a top perspective view of a check-valve assembly according toan alternative embodiment of the disclosure;

FIG. 10 is a cutaway perspective view of the FIG. 9 assembly;

FIG. 11 shows component parts of the assembly shown in FIGS. 9-10, and acompleted assembly module;

FIGS. 12-13 show check-valve module components and an installedcheck-valve module to be replaced, according to an embodiment of thedisclosure;

FIG. 14 is an exploded view of an additional check-valve module,according to an embodiment of the disclosure;

FIG. 15 is an exploded view of a check-valve module according to anotherembodiment of the disclosure;

FIG. 16 is a perspective view of the FIG. 15 module in assembled form;

FIG. 17 is an exploded view of the FIG. 15 module with components forinstallation in surrounding structure;

FIG. 18 is a cross-sectional view of the FIG. 17 module in assembled andinstalled form;

FIG. 19 is an exploded view of a check-valve module according to anotherembodiment of the disclosure;

FIG. 20 is a perspective view of components of the FIG. 19 module, inassembled form;

FIG. 21 is an exploded view of the FIG. 20 components;

FIG. 22 is a perspective view of the FIG. 20 components assembled in analternative configuration;

FIG. 23 is a cross-sectional view of the FIG. 19 module, installed in anoutlet configuration;

FIG. 24 is a cross-sectional view of the FIG. 19 module, installed in aninlet configuration; and

FIG. 25 is a schematic view of a substrate container assembly with theFIG. 24 module installed in inlet and outlet configurations.

DETAILED DESCRIPTION

FIG. 1 illustrates an example wafer container assembly 2 in whichembodiments of the disclosure can be implemented. Container assembly 2includes wafer carrier 4, bottom door 6, and enclosure portion 8. Bottomdoor 6 is adapted to sealably couple with enclosure portion 8 to definean interior space that can be isolated from ambient atmosphere 10. Asshown in FIG. 1, wafer carrier 2 can comprise a plurality of elements12, such as shelves, that can hold and position a plurality of siliconwafers or other substrates within wafer carrier 2. Generally, elements12 hold and position the substrates such that contact between adjacentwafers is minimized, which can reduce damage to the substrates that canoccur during processing and/or transportation.

FIG. 2 illustrates an example bottom door 6 in more detail. Section 6comprises access structures in the form of openings 14, 16. According toone embodiment, opening 14 facilitates the introduction of gases orother fluid transfer into container assembly 2. Similarly, opening 16facilitates the removal of gases or other fluid transfer out ofcontainer assembly 2, e.g. such that gas or fluid located withincontainer assembly 2 can be vented to the ambient atmosphere. Thus,according to one embodiment, opening 14 is an inlet, while opening 16 isan outlet. Although FIG. 2 illustrates an embodiment where bottom door 6comprises two openings 14, 16, embodiments having four, five, six, ormore access structures located in bottom door 6 are contemplated and arewithin the scope of the present disclosure. It should also be understoodthat embodiments of the disclosure can be implemented in a section ofcontainer assembly 2, or similar container, that is a non-removable,non-openable section.

As illustrated in FIG. 2, openings 14, 16 accommodate, or are disposedin association with, valve assemblies or modules according to theembodiments of the disclosure, illustrated generally at 20, 22. Valveassembly 20 is positioned at or within opening 14 to seal opening 14,and valve assembly 22 is positioned at or within opening 16 to sealopening 16. Valve assemblies 20, 22 each create a seal against theinterior of their corresponding opening 14, 16, and each provide atleast one bore or passageway for passage of gas or other fluids. One ofordinary skill in the art will recognize that the size, cross-sectionalshape, and other features of openings 14, 16 and valve assemblies 20, 22can be guided by gas flow requirements, operating pressures, and othercharacteristics of a particular wafer container assembly or environment.Specific embodiments of valve assemblies 20, 22 and associatedcomponents will be described with respect to FIGS. 6-25.

FIGS. 3-4 illustrate another configuration of a wafer container assembly23, known as a FOUP (front opening unified pod) or FOSB (front openingshipping box), in which embodiments of the disclosure can beimplemented. Container assembly 23 generally includes door 24 andcontainer portion 26. Container portion 26 has front opening 30 leadinginto container interior 32 where a plurality of wafers W are retained onwafer shelves 35. Door 24 has key access holes 36 and latch mechanism 38partially illustrated in the interior of the door enclosure. Latch tips41 engage recesses 39 in the container portion door frame 40.

Container assembly 23 has purge capabilities with a pair of forwardpurge ports 48 and rearward purge ports 54. Ports 48, 54 have purgegrommets 50 secured into access structure or grommet receiving structure51, located on bottom 52 of container assembly 23 and optionallyassociated with each port 48, 54. Check valves 56 according toembodiments of the disclosure are inserted into the grommets to formvalve assemblies that control the direction of purging gas fluid flow.Additionally, tubular environmental control components configured aspurge towers 60 are illustrated, which optionally receive grommets 62and check valves 64. Specific embodiments of valve assemblies, grommets,check valves, and associated components will be described with respectto FIGS. 6-25.

FIG. 5 illustrates one type of access structure or receiving structure51 disposed in a wall or cover of a substrate container, for examplebottom 52 or side cover of container assembly 23, according to anembodiment of the disclosure. Structure 51 constitutes inlet or outletstructure for fluid passage into or out of container assembly 23, and isconstructed to receive and/or accommodate valve assemblies and modulesalong central axis 66. Access structures or retaining structurescontemplated in this disclosure function as purging ports and optionallyinclude retaining structures having geometry specially adapted tosealably engage grommets or valve assemblies and modules. The grommetsand assemblies/modules themselves optionally include various sealingfeatures for creating fluid-tight contact with certain interior featuresof associated access or retaining structures.

FIGS. 6-25 illustrate various valve assemblies and modules, according toaspects of the disclosure, that can be implemented in or with respect todoors, side walls, bottom walls, purge tubes, or other components ofwafer carriers such as those illustrated in FIGS. 1-5, or other types ofcarriers and containers.

FIGS. 6-25 additionally illustrate various types of grommets or otherstructures used in sealing openings or ports in substrate containers,according to embodiments of the disclosure. Generally speaking, thegrommets or structures include a body having a bore located within thebody, the bore extending along the major axis of the body. Additionally,embodiments of grommets of the present disclosure comprise an operationelement located with the bore. The operation element can comprise acheck valve that can regulate the flow of gas or other fluids throughthe bore, a filter, a sensor or combinations thereof. The check valvesemployed in the present disclosure can be oriented within the bore suchthat the grommets can be used to seal both inlet and outlet openings onsubstrate container doors and/or enclosures. Additionally, the design ofthe grommet body optionally can facilitate sealing of the openingwithout the need for additional O-rings attached to the grommet.Furthermore, embodiments of grommets of the present disclosure cancombine a grommet body, check valve and/or filter into an integralcartridge or module, which can improve the overall sealing ability ofthe grommets and can facilitate easier construction of substratecontainer assemblies. In some embodiments, the grommets have an axialheight from about ¼ inch to about 1 inch, while in other embodiments thegrommets can have an axial height from about ⅜ inch to about ¾ inch.Additionally, embodiments of grommets of the present disclosure can havea diameter from about ¼ inch to about 1.5 inches, while in otherembodiments the grommets can have a diameter from about ½ inch to about¾ inch. One of ordinary skill in the art will recognize that additionalranges of axial height and diameter of the grommets are contemplated andare within the scope of the present disclosure.

The check valve members as illustrated have a disk and a valve seatconnection portion configured as a central stem centrally attached tothe disk. In other embodiments, the valve seat connection portion may beat a periphery of the disk such that the disk operates as a flappivoting about the connection portion.

The grommets can be distinguished from O-rings known in the art in anumber of ways. For example the grommet configuration provides anelastomeric element that is generally of a cylindrical configurationwith a bore extending therethrough, the bore itself having a cylindricalconfiguration. The bore is of sufficient length to contain totally orsubstantially the entire length of an operational component insertedtherein. The grommet preferably has at least one planar surface arrangedto be normal to the axis of the grommet. Such surface can be utilized toeffectively provide a seating surface for a nipple or nozzle as part ofa purging system. Volumetrically, the grommet is preferably larger thatthe operational component, or any associated structure, contained withinthe grommet. The grommet preferably has a cross sectional area taken inan axial plane whereby the cross sectional area of the grommet isgreater that the cross sectional area of the opening extending axiallytherethrough. The grommet preferably has an axial length that is greaterthan the diameter of the opening or bore extending axially through thegrommet. Grommets described herein optionally have a non-circularcross-section in elevation, cylindrical inner facing surfaces,cylindrical outer facing surfaces, and planar end surfaces.

Turning to specific aspects of the disclosure, FIGS. 6-8 illustrate afirst type of check-valve assembly 100. Check-valve assembly 100includes grommet 105 having internal structure 108 defining valve seat110. Internal structure 108 and valve seat 110 are disposed atsubstantially a midpoint of grommet 105 along its axial length, thoughother positions along the axial length are also contemplated. Grommet105 optionally is a purge grommet, defining a purge grommet interfaceadapted to sealingly connect to a purge nozzle for introducing orwithdrawing gases from the interior of a substrate container.

Umbrella check valve member 115 is disposed and held within elastomericgrommet 105 to engage/disengage valve seat 110 and thereby restrict orallow fluid flow through check-valve assembly 100. Apertures 118 throughinternal structure 108 of grommet 105 allow fluid flow along the axiallength of grommet 105.

As illustrated in FIG. 7, for example, umbrella check valve member 115is oriented such that purge gas or other fluid is allowed to flow out ofthe substrate container interior, as indicated by arrow 125, for egressthrough check-valve assembly 100. Umbrella check valve member 115engages valve seat 110 to disallow fluid flow in an opposite, oringress, direction. Umbrella check valve member has a stem portion 116and a disk portion 117.

Internal structure 108 of grommet 105 additionally defines second valveseat 120, illustrated in FIG. 7, on an opposite side of structure 108relative to first valve seat 110. Orienting umbrella check valve member115 within grommet 105 to engage and disengage valve seat 120, insteadof valve seat 110, permits fluid to flow in a direction opposite to thatindicated by arrow 125, e.g. for ingress through check-valve assembly100 and into the substrate container interior. Umbrella check valvemember 115 then engages valve seat 120 to disallow fluid flow in anopposite, or egress, direction.

According to one embodiment, stem 116 of umbrella check valve member 115is press-fit into central bore 130 of grommet 105, as viewed in FIG. 8,for example, for flow ingress. Alternatively, umbrella check valvemember 115 is press-fit into central bore 130 from a bottom side ofgrommet 105, again as viewed in FIG. 8, for flow egress. Grommet 105thus is constructed to retain valve member 115 in a first position,illustrated in FIG. 7, in which valve member 115 engages and disengagesvalve seat 110 to allow fluid flow only in one direction throughassembly 100, as indicated by arrow 125 (egress). Grommet 105 also isconstructed to retain valve member 115 in a second position, e.g.inserted from the top side of grommet 105 as viewed in FIG. 8, to allowfluid flow only in a second direction, opposite to arrow 125 (ingress).Grommet 105, internal structure 108, and valve seats 110, 120, togetherform a substantially “H”-shaped cross section, as shown in FIG. 7.

Grommet 105 is manufactured by injection molding a thermoplasticelastomer, according to one embodiment, or casting a rubber-likecompound such as FKM. Accordingly, grommet internal structure 108 andvalve seats 110, 120 are integrally formed as one-piece with grommet105. Grommet 105 and seats 110, 120 are elastomeric and have associatedelastomeric properties. Umbrella check valve member 115 is also formedby injection molding the same or similar materials, for example.According to one embodiment, a cracking pressure of umbrella check valvemember 115 is between about 0.5 inches and about 5 inches H2O (betweenabout 0.125 kPa and about 1.25 kPa). Other suitable manufacturingprocesses for grommet 105 and valve member 115 will be apparent to thoseof ordinary skill in the art upon reading this disclosure.

Forming one or more of umbrella valve member 115 and valve seats 110,120 out of elastomeric materials provides a number of advantages,including easy assembly, non-critical relative size, excellent sealingperformance, and reduction in the number of parts needed to achievethese advantages. Check-valve assembly 100, for example, is formed ofjust two pieces—elastomeric valve member 115 and elastomeric grommet 105with its internal, integral, elastomeric valve seat(s). Valves andgrommets are readily assembled for quick and effective installation,with minimal likelihood of error. One particular size or shape ofgrommet is not limited to receive one particular size or shape of valve,allowing interchangeability of parts and greater assembly flexibility.Additionally, elastomeric components are less likely to generateparticulate contamination, as compared to e.g. metal springs or othercomponents.

Returning to FIG. 6, grommet 105 and its associated valve are sealinglyreceived within purge body housing 135. Grommet 105 optionally includesone or more circumferential protrusions or sealing rings 140 to sealagainst the interior surface of purge body housing 135. Additionally,filter 145 is disposed between grommet 105 and an interior of purge bodyhousing 135. Embodiments of filter 145 and other filters disclosedthroughout this patent application include particle filters of suitabletechnology, such as HEPA filtration or the like. Purge body housing 135also optionally includes O-ring 150 to aid in forming a sealingconnection with access structure or receiving structure 155 associatedwith a substrate container assembly. Purge body housing 135 is retainedwith respect to the substrate container assembly within structure 155 byretaining clips 156, for example, or by other suitable retainingstructure. Together, purge body 135, grommet 105, valve member 11, andfilter 145 form a check-valve assembly or module that is easilyinstallable and replaceable in access structures associated with varioustypes of substrate containers.

FIGS. 9-11 illustrate an additional embodiment of check-valve assembly157, in which grommet 158 receives housing 160, formed of asubstantially rigid plastic material, for example. Housing 160 retainsumbrella check valve member 162 for engagement with valve seats 165 or170, formed on opposite sides of housing internal structure 172, in amanner similar to that described with respect to FIGS. 6-8. Internalstructure 172 and valve seats 165, 170 are disposed at a substantialmidpoint of housing 160 along its axial length, and are disposed at asubstantial midpoint of grommet 158 along its axial length, althoughplacement closer to the ends of housing 160 and grommet 158 are alsocontemplated. Forming housing 160 and valve seats 165, 170 from asubstantially rigid material, instead of molding them as an integralpart of elastomeric grommet 158, provides additional structuralresistance to external compressive forces that may act on grommet 158,for example. Stem 161 of valve member is retained in a central aperture163 of the valve seat.

Check valve member 162 is optionally identical to check valve member 115of the previously described embodiment, or constructed of differentshape or size to fit a particular housing 160. As with the previousembodiment, different sizes or shapes of valve member 162 can beaccommodated within housing 160, providing greater flexibility inmanufacturing and inventory, among other advantages. Housing 160 definescircumferential protective sidewall 175 to surround umbrella check valvemember 162. Housing 160 with protective sidewall 175 protects umbrellacheck valve member 162 from deformation or other damage that can becaused by external pressure acting upon grommet 158, for example uponinsertion into access structure or other structure associated with asubstrate container. Check-valve assembly 157 is formed of only threepieces: elastomeric valve member 162, housing 160, and grommet 158.Together, grommet 158 and housing 160 with structure 172 define asubstantial “H”-shape in cross section, as shown in FIG. 10. Grommet 158with housing 160 and the umbrella check valve member 162 are togetherinserted into housing 178 to form completed check valve module 180, allas shown in FIG. 11. Check valve module 180 is readily removablyinstalled in associated retaining or access structure of a suitablesubstrate container.

One aspect of the disclosure includes retrofitting or replacing anexisting check-valve assembly or module with one like that shown inFIGS. 6-8 or FIGS. 9-11. According to one example, shown in FIGS. 12-13,check-valve assembly 200 to be replaced includes purge grommet 203,frame 205 disposed within grommet 203, frame 205 supporting plunger 210,spring 215, and O-rings 220, 225, all installed within tubularenvironmental control structure 230 (FIG. 13) or other access orreceiving structure. In the event installation forces, other forces, ornormal wear have caused check-valve assembly 200 to be damaged orotherwise in need of replacement, aspects of the disclosure involveremoving assembly 200 from structure 230 and replacing it withcheck-valve module 180 of FIGS. 9-11 or the check valve module of FIGS.6-8, for example. Alternatively, it is possible to effect repair byremoving frame 205 and its associated components from within purgegrommet 203, and replacing them with housing 160 and associated umbrellacheck valve member 162. Purge designs such as those shown in FIGS. 12-13potentially risk substrate contamination due to the presence of spring215, in certain conditions, providing additional advantages toreplacement in the manner described.

FIG. 14 shows an additional check-valve module 240 suitable for use withvarious substrate containers, according to an embodiment of thedisclosure. Module 240 includes elastomeric umbrella valve member 245inserted and retained within a central bore 250 of valve block 255.Filter 260 and filter cap 265 are disposed within or at the end ofelastomeric or substantially rigid valve block 255. Valve block 255snaps into or is otherwise retained within valve body 270. Interfacesurface 275 of valve body 270 sealingly connects to access or otherstructure associated with a substrate container. As with previousembodiments, umbrella valve member 245 can be inserted into bore 250 inan opposite orientation, i.e. from within valve body 255 as viewed inFIG. 14, to reverse the permissible direction of fluid flow.

As an additional embodiment, FIGS. 15-16 illustrate check-valve assembly300 in unassembled and assembled states, respectively. Assembly 300comprises substantially rigid valve seat 305 that retains elastomericumbrella check valve member 310 within central bore 315. O-ring 320 isretained within circumferential groove 325 of valve seat 305 to sealvalve seat 305 to surrounding structure. As shown in FIGS. 17-18,assembly 300 is combined with and stacked between purge grommet or otherelastomeric interface 330, and filter component 335, in the form of afilter disc pack, for example, to form a module installed within tubularenvironmental control structure 340. Filter component 335 abuts againstinternal stop 342 of control structure 340 to prevent over-insertion,according to one embodiment. As with previously described embodiments,the orientation of valve member 310 with respect to valve seat 305, orthe orientation of valve member 310 and valve seat 305 together withrespect to surrounding structure, can be reversed, to reverse thedirection of permissible flow through the module.

FIGS. 19-24 illustrate purge module 350, according to another embodimentof the disclosure. Module 350 includes valve housing 355, optionallyformed of an elastomeric material and defining valve seats 360, 365.Elastomeric umbrella check valve member 370 is received within centralbore 375 of housing 355. Filter grate 380 and filter 385 are in fluidcommunication with check valve member 370 and the remaining components.Housing 355 and its related components are received within injectionmolded diaphragm interface 390, which itself is received and retainedwithin outer purge body 395 to form completed module 350. In use,optional O-ring 400 is received within groove 405 of purge body 395 andsealingly engages purge body 395 and module 300 with respect tosurrounding structure.

FIGS. 20-21 show umbrella check valve member 370 press-fit into bore 375against valve seat 360 in an outlet configuration, for example,permitting fluid flow with respect to an associated substrate containeronly in an outward or egress direction. FIG. 22 shows valve member 370press-fit from an opposite end of housing 355 into central bore 375 inan inlet configuration, permitting fluid flow with respect to anassociated substrate container only in an inward or ingress direction,for example. FIG. 23 shows assembled module 350 with umbrella checkvalve member 370 installed in an outlet configuration, and FIG. 24 showsassembled module 350 with umbrella check valve member 370 installed inan inlet configuration, according to embodiments of the disclosure.

FIG. 25 shows module 350 of FIG. 24 installed in forward and reverseconfigurations with respect to substrate container assembly 420. Inconfiguration 425, module 350 serves as a fluid outlet, permitting fluidto flow only away from the interior of substrate container assembly 420.In configuration 430, module 350 is inserted into receiving structure ofcontainer assembly 420 in a direction opposite to that of configuration425, causing module 350 to serve as a fluid inlet and thus permit fluidflow only toward the interior of substrate container assembly 420. Thetwo modules 350 of FIG. 25 can be identical or substantially identicalin structure but reversed in relation to each other in installation, topermit fluid flow only in opposite directions relative to the substratecontainer.

In operation, inlet and outlet arrangements disclosed in FIG. 25 andelsewhere throughout this disclosure can function in concert during apurging activity in which existing air or gas within the interior of thesubstrate container is displaced by newly introduced air, gas, or otherfluid. A vacuum source is optionally coupled to the interior volume ofthe container by an outlet nozzle that is adapted to interface with acontact surface of an associated valve assembly or module disclosedherein. When force is exerted by the outlet nozzle into an associatedelastomeric grommet, the grommet compresses, but maintains its sealagainst the sealing inner surfaces of associated access or retainingstructure of the container, and against the outer surface of valveassembly or module.

As vacuum is coupled with the interior volume of a substrate container,existing fluid in the volume is drawn out of the substrate containerthrough an outlet as described herein, while, while replacement fluid isdrawn in through an inlet, including through an associated filter. In arelated embodiment, a replacement fluid source is coupled with theinterior volume via an inlet nozzle having geometry similar to theoutlet nozzle and coupled with an inlet grommet or assembly/module inthe same manner in which the outlet nozzle is coupled with the outletgrommet or assembly/module. In another embodiment, no outlet nozzle isused. The inlet nozzle carries pressurized replacement fluid into theinterior volume of the container, and displaced fluid simply existsthrough the outlet arrangement.

Check-valve assemblies and modules according to aspects of thedisclosure provide a number of advantages over the prior art. Theassemblies and modules are designed to be readily interchangeable, incertain cases, leading to easy repair and replacement of onemodule/assembly with another. Elastomeric components, as opposed to e.g.metal springs, reduce the risk of contaminants entering the interior ofa substrate container. The number of parts within a check-valve assemblyis substantially reduced, in some cases to just two pieces: a grommethaving internal structure defining one or more valve seats, and anassociated umbrella check valve member. Embodiments disclosed hereinreduce the possibility of damage to components during installation,reducing the possibility leaking check valves. Embodiments of thedisclosure can be used with containers accommodating multiple differentsubstrates and sizes, for example 300 mm and 450 mm silicon wafers.Additionally, check valves according to embodiments of the disclosureare used to control ingress and egress of various gases or other fluids,for example clean dry air, nitrogen, or other suitable purge gas intoand out of various microenvironments. Aspects of the disclosure alsoprovide advantages over e.g. duckbill-type check valves disclosed incommonly assigned U.S. Pat. No. 7,201,276, which is incorporated hereinby reference. As one example, umbrella valve members disclosed hereinare normally or naturally closed, in a flow-obstructing position,whereas a duckbill-type valve needs to be preloaded with pressure in aclosed position.

Generally, the various grommets, assemblies, and modules disclosedherein can have the same cross-sectional shape as the receivingstructure in which they are disposed, or as the openings that they aredesigned to seal. For example, in one embodiment, grommets have agenerally cylindrical shape with a generally circular cross-section.However, one of ordinary skill in the art will recognize a variety ofgrommet body geometries, for example tapered geometries, are within thespirit of the present disclosure. In one embodiment, inlet and outletgrommets or inlet and outlet modules disclosed herein are identicalparts. Thus, various components of the present disclosure can be used toseal both inlet and outlet openings using the same component elements.In related embodiments, the umbrella check valve members disclosedthroughout this application are identical parts. Grommets and modules ofthe present disclosure further include retaining features for securelyholding filters and related components. Thus, the various modules andcomponents described herein can be formed as pre-assembled operationalsubassemblies. Additional features of grommets, valve members andassociates components are disclosed in U.S. Pat. Nos. 8,727,125 and8,783,463, which are incorporated herein by reference. Additionalcarriers in which embodiments of the disclosure can be implemented aredescribed in U.S. Pat. No. 6,428,729, which is hereby incorporated byreference.

The grommets, valve members, and other components of the presentdisclosure can be composed of any material suitable for use insemi-conductor processing applications including polymers andelastomers. In some embodiments, the grommet body and flanges can becomposed of a fluoroelastomer. Examples of fluoroelastomers are soldunder the trade name Viton® by Dupont Dow Elastomers. Additionally, insome embodiments, the elastomeric grommet body or grommet can have afluoropolymer, or other inert polymer, coated onto to the surface of thegrommet to isolate the elastomeric substance from the interior of thesubstrate container. Generally, the polymer or fluoropolymer coatingshould have some flexibility such that the sealing characteristics ofthe elastomeric grommet body are maintained.

The embodiments described above are intended to be illustrative and notlimiting. Additional embodiments are within the claims. Although thepresent invention has been described with reference to particularembodiments, those skilled in the art will recognize that changes may bemade in form and substance without departing from the spirit and scopeof the invention.

1. A substrate container, comprising: a container portion having an openside or bottom; a door to sealingly close the open side or bottom, oneof the door and the container portion defining access structure; aplurality of wafer shelves for holding the wafers, the shelvespositioned on one of the door and container portion; a two-piececheck-valve assembly, the check-valve assembly being retained withrespect to the access structure to provide fluid communication with aninterior of the substrate container; the check-valve assemblycomprising: a grommet, the grommet formed of an elastomeric mated anelastomeric valve seat disposed within the grommet, the elastomericvalve seat being integrally formed with the grommet; and an elastomericvalve member disposed within the grommet, the elastomeric valve memberbeing engagable with the elastomeric valve seat to restrict fluid flowthrough the check-valve assembly with respect to the interior of thesubstrate container, and the elastomeric valve member being disengagablefrom the elastomeric valve seat to allow fluid flow through thecheck-valve assembly with respect to the interior of the substratecontainer.
 2. The substrate container of claim 1, wherein theelastomeric valve comprises an umbrella valve member, the umbrella valvemember disposed to sealingly engage with the valve seat within thegrommet to restrict fluid flow through the check-valve assembly.
 3. Thesubstrate container of claim 1, wherein the grommet is a purge grommetconstructed to sealingly connect to a purge nozzle for introducing fluidto or withdrawing fluid from the interior of the substrate container. 4.The substrate container of claim 1, further comprising: a purge bodyhousing adapted to sealingly receive the grommet and to sealinglyconnect to the substrate container; and a filter disposed between thepurge grommet and an interior surface of the purge body housing.
 5. Thesubstrate container of claim 1, wherein the valve seat is a first valveseat, the grommet further comprising a second valve seat disposed withinthe grommet opposite the first valve seat, the second valve seat beingintegrally formed with the grommet; wherein the grommet is constructedto retain the elastomeric valve member in a first position, in which theelastomeric valve member engages and disengages the first valve seat toallow fluid flow only in one direction through the check-valve assemblywith respect to the interior of the substrate container; further whereinthe grommet is constructed to retain the elastomeric valve member in asecond position, in which the elastomeric valve member engages anddisengages the second valve seat to allow fluid flow only in a seconddirection, opposite to the first direction, through the check-valveassembly with respect to the interior of the substrate container. 6-10.(canceled)
 11. A substrate container, comprising: access structure forfluid communication with an interior of the substrate container; aplurality of substantially horizontal spaced apart substrate shelveswithin the interior of the container; an elastomeric, substantiallycylindrical interface readily removably coupled with the accessstructure; a housing received within the interface, the housing definingat least one valve seat; and an elastomeric disk shaped check valvemember secured within the housing to control fluid flow through theinterface by engaging the at least one valve seat; wherein the housingis formed of a substantially rigid material to protect the elastomericumbrella check valve member from damage.
 12. The substrate container ofclaim 11, wherein the housing defines a first valve seat and a secondvalve seat, the housing being constructed to secure the elastomeric diskshaped valve member in a first position to selectively engage the firstvalve seat and allow fluid flow only in a first direction; the housingfurther being constructed to secure the elastomeric valve member in asecond position to selectively engage the second valve seat and allowfluid flow only in a second direction, opposite to the first direction.13. The substrate container of claim 11, wherein the housing is formedof a substantially rigid material and press-fit into the interface. 14.The substrate container of claim 13, wherein the interface is a purgegrommet interface and the elastomeric disk shaped valve member is anumbrella valve member.
 15. A substrate container, comprising: acontainer portion having a container wall defining a container interior,the container portion further having a plurality of substantiallyhorizontal spaced apart substrate shelves disposed within the interior;at least one substantially tubular environmental control component fordirecting fluid flow into the container interior; a check-valve assemblydisposed within the control component, adapted to allow fluid flow intothe substrate container through the control component, the check-valvemember assembly comprising: a substantially cylindrical valve seatportion; and an elastomeric umbrella check valve member held within thevalve seat portion to substantially disallow fluid flow out of thecontainer through the control component; and an elastomeric interfacestacked with the check-valve assembly, an end of the elastomericinterface being sealingly engaged with an end of the check-valveassembly, and an outer circumference of the elastomeric interface beingsealingly connected to the control component.
 16. The substratecontainer of claim 15, further comprising: a filter component stackedwith the check-valve assembly, the filter component being sealinglyengaged with and disposed at another end of the check-valve assemblyopposite to the elastomeric interface.
 17. The substrate container ofclaim 16, wherein the filter component abuts against a stop disposedwithin the control component, to prevent over-insertion within thecontrol component.
 18. The substrate container of claim 15, wherein thevalve seat portion is in the shape of a cylindrical disk and defines acircumferential groove; further wherein the substrate containercomprises an O-ring disposed within the groove to sealingly connect thecheck-valve assembly to the control component.
 19. The substratecontainer of claim 15, wherein the valve seat portion is formed of asubstantially rigid material.
 20. A substrate container, comprising: anexternal container portion defining a container interior; a plurality ofsubstantially horizontal spaced apart substrate shelves within thecontainer interior; at least one port defined in the external containerportion, the port adapted to fluidly communicate with the containerinterior; and a purge module operably coupled with the at least one portand adapted to allow and disallow fluid communication with the containerinterior, the purge module comprising: a valve body housing, the valvebody housing defining a first valve seat and a second valve seat; andair elastomeric umbrella check valve member held within the valve bodyhousing, the valve body housing being constructed to hold theelastomeric umbrella check valve member in a first position to engageand disengage the first valve seat to allow fluid flow only into thecontainer interior; the valve body housing being constructed to hold theelastomeric umbrella check valve member in a second position to engageand disengage the second valve seat to allow fluid flow only out of thecontainer interior.
 21. The substrate container of claim 20, wherein thevalve body housing is substantially rigid and defines a central bore,the elastomeric umbrella check valve member being press-fit into thecentral bore from one end thereof to engage and disengage the firstvalve seat; the elastomeric umbrella check valve member being press-fitinto the central bore from an opposite end thereof to engage anddisengage the second valve seat. 22-28. (Canceled)